Ok, interesting episode. This is what I gathered from it. Audio was Keyhole quality so I'm not sure about any of this .

Spoiler for ep20:

1) Kanba and Masako are siblings.

2) Shouma seems to be the only real Takakura, and it's not related neither to Kanba or Masako.

3) Himari is just the kid from a random neighbor.

4) Shouma Masako Kanba and Mario were the kids of the members of KIGA, who where planing something to "change the world" or some shit.

5) Shouma and Kanba have both KIGA apples of their own. What does this mean, I don't know.

5) Shouma meets Himari by chance on an abandoned building or something like that (maybe it's not abandoned though ). He befriends her and gives her his scarf (yep, the scarf is his!). More like the kid of neighbor she seems like an orphan and Keyhole was shit so I don't know which is it.

6) When Himari is taken to the Broiler (it's still ambiguos whether it's a real place) Shouma goes to her rescue. I can see how at the point, much like Momoka for Tabuki, Shouma became the only reason Himari had to live for.

7) Back in the present, it seems Shouma was telling all this to Ringo. Ringo is really supportive of him, but I don't know what is her role in all this now.

8) Also back in the present, Kanba meets with the Takakura again, and says he's the only one who can save Himari....

.... cue for confrontation between the brother?? I don't know. And I don't care too much about it either, to be honest.